148 THE COMMON FROG. [chap. 



CHAPTER X. 



SUMMARY. 



Taking a rapid retrospect of the course we have 

 pursued, we find that in seeking to decide as to 

 " What is a Frog ? " our inquiry into its absolute 

 structure has made known to us an animal of pecu- 

 liarly specialised and perfect organization. This has 

 been shown to us pre-eminently by the study of its 

 skeleton. We have especially noted its skull, its 

 wonderfully short vertebral column, its utterly ano- 

 malous pelvis, and its scarcely less anomalous foot. 

 The flesh which clothes that skeleton has been seen 

 to exhibit distinct muscles wonderfully like our own, 

 those of the foot, indeed, exceeding ours in number, 

 and being a very marvel of complexity. We have 

 met with a nervous system ministered to by delicate 

 organs of sense, and noted for the ready response to 

 stimuli, made by even separated parts of it, as evi- 

 denced by strikingly co-ordinated complex move- 

 ments. We have found the circulation to be carried 

 on by a heart which, at first sight, seems too struc- 

 turally imperfect to distribute the venous and arterial 



